a {
    color: red;
    background-color: bisque;
}

a:hover {
    color: gold;
    font-size: 150%;
}

a:active {
    color: black;
    font-size: 50%;
}

a:visited {
    color: green;
}

.baidu:focus {
    background-color: red;
    width: 100px;
    height: 50px;
}

div div {
    color: blue;
}

div>div {
    color: purple;
}

div>div>ul {
    font-size: 200%;
}

h1+p:before {
    content: "老番茄是";
}

div>p:after {
    content: "?";
}

div .fruit::before {
    content: "还是";
}

h1~p {
    color: brown;
}